Diagnosing The 2nd Gen GM HEI Ignition System Auto and Marine Using Common Tools

This is a demonstration on how to diagnose a no spark, weak spark, and no injector pulse concerns with this system commonly found on 87-95 GM trucks with 4.3, 5.0, 5.7, and 7.4 engines. It was also used in the some other engines such as the 2.5 and 2.8 as well. It was very common to find these ignition systems as factory equipment on marine fuel injected engines with MEFI controllers from 94-03. It was also a very common ignition system upgrade the the marine industry on carbureted engines and was called the Delco Voyager ignition system. Crusader marine started engines this system on their carbureted XL series engines in 1992. It’s a popular system and these techniques shown will help you diagnose a start/stall, stalling at idle, no spark, no injector pulse or both.

[@johnmiller632]

best marine toutorials on u-tube/thank you

[@themikeanic1535]

Phenomenal! Clear and precise!

[@thomasnicholas8480]

Very informative, I installed an HEI systems on my CC 327F engines.

[@scottsmith2869]

Could you do a video on the code 42 please?
I have this issue. It runs roughly and rich. Pops through the exhaust. It throws a code 42. When I replaced the pickup coil and the model it will not run. If I put the old model on it runs poorly. But put another new module in and it will not run. Any help would be appreciated. Thank you for your videos

[@genesmith4019]

I’m getting 300 Mv AC at the magnet but no spark when supplying 12.6 through tester to green wire.
Does that mean module is problem?

[@nathangen]

when you are testing continuity on the 2 plug going to the ICM what cable did you disconnect first?

[@LakelandAutoMarine]

I don’t understand your question. I unplug the pickup coil and connect an A/C meter between the two wires. Ohm it first and then crank it and check the A/C output.